Cartilage tissue function Flashcards
What are the main functions of cartilage tissue?
Protection and cushioning of bones
Provides a smooth gliding surface within joints
Supports flexible tissue structures
Provides a transition tissue tendons/ligaments and bones
What do cartilage protect bones from?
Cartilage protect bones from compressive joint loads
What features do cartilage have that provide it with the ability to support flexible structures?
Cartilage is a highly deformable and compressible elastic connective tissue
Allows it to support flexible tissue structures
What is an enthesis?
Connective tissue between bone and tendon/ligament structures
Where are synovial joints found?
Covering the articulating joints
What role does cartilage play in the funcitoning of synovial joints?
Cartilage tissue is central to the functioning of synovial joints
What are the 3 types of cartilage found in the adult body?
Fibrocartilage
Hyaline cartilage
Elastic cartilage
Where is fibrocartilage found?
Intervertebral discs
Joint capsules
Ligaments
Features of fibrocartilage
Strongest kind of cartilage
Alternating layers of hyaline cartilage matrix and thick layers of dense collagen
No perichondrium
How are the collagen fibres oriented in fibrocartilage?
Oritented in the direction of functional stresses
Role of fibrocartilage
Transitional layer between hyaline cartilahe and tendon/ligament
Where is hyaline cartilage found?
Ribs
Nose
Larynx
Trachea
Features of hyaline cartilage
Most abundant form
Weakest
Glassy appearance
Contains dispersed, strengtening type II collagen
Has perichondrium
Role of hyaline cartilage
Part of the endochondral ossification process
Acts as a model anlagen
Precursor of bone
Structural features of elastic cartilage
Chondrocytes found in threadlike network of elastic fibres within the matrix
Has a perichondrium
Role of elastic cartilage
Provides strength and elasticity
Maintains shape of structures
Example of a structure that the elastic cartilage maintains the shape of
Ear
What makes cartilgae disntict from other tissue types?
Has only 1 cell type = chondrocyte
Contains highly specific and abundant ECM
Lacks blood vessels and innervation
Very limited regenerative capacity
Are chondrocytes found in high numbers in the cartilage?
NO
Chondrocytes are found in very low numbers relative to the matrix volume
Why is cartilage described as hydrodynamic?
Cartiage has high mechanical resiliency to compressive loading
How do cartilage receive nutrients since the tissue has no blood supply?
Receives nutrients via mass exchange
Diffusion
Why is cartilage described as a bradytrophic tissue?
Cartilage has a slow metabolism
What is the half life of cartilage?
Half life is estimated as 117 years
Built for life - does not undergo extensive remodelling like bone
What percentage of the ECM is water in hyaline cartilage?
75%
What are the 4 structurally distinct zones of the hyaline cartilage ECM called?
Articular surface (10-20% of volume)
Middle zone (40-60% if volume)
Deep zone (30-40% of volume)
Calcified zone
What is the role of the articular surface of the hyaline cartilage?
Provides smooth glinding surface for joints
Supported by 2-3 layers of chondrocytes
What is the largest zone of the hyaline cartilage?
Middle zone
Structure of the middle zone
Chondrocytes and collagen fibers in cartilage surface orientation
Structure of the deep zone
Type II Collagen fibers in perpendicular orientation to joint
Highest proteoglycan concentration
Round chondrocytes in columnar orientation
Role of the calcified zone
Forms the transition tissue between cartilage and subchondral bone
What separates the deep zone from the calcified zone?
Tidemark
Made of parallel collagen type I fibers
